GD&T Total Runout Definition

In GD&T, total runout is a complex tolerance that controls a feature‘s straightness, profile, angularity, and other geometric variation.  Total runout is different than runout because it applies to an entire surface simultaneously instead of individual circular elements.

An example of total runout tolerance is shown below.  The top figure shows a total runout tolerance applied to a horizontal surface.  The boxed symbols can be read “this entire surface must have full indicator movement (FIM) of less than 0.1 relative to datum A”.  The lower figure shows how total runout is verified.  Note that the indicator is applied all along, and perpendicular to the surface to which the tolerance is applied.

total_runout3